Unit 3 ExamREVIEW QUESTIONS

One group on the periodic table is the least reactive. How many valence electrons do these elements have?•8 (OCTET, NOBLE GASES)

Mendeleev was the first to make his version of the periodic table and organized it by what property?

Atomic Mass

The scientist who reorganized the periodic table by atomic number was ______

Moseley

Which scientist is credited with discovering the nucleus? What was the name of the experiment that he used?

Rutherford; gold foil experiment

Which scientist studied experiments with light to describe the circular orbitals (or energy levels) where electrons exist?

Bohr

Which scientist proved the existence of subatomic particles?

•THOMSON (DISCOVERY OF NEGATIVELY CHARGED PARTICLES AKA ELECTRONS)

The existence of _________ disproved Dalton’s theory that all atoms of an element were identical.

Isotopes (same element, different masses)

Set up your white board like this

# protons # neutrons # electrons

For the following atoms or ions, give the numbers of protons, neutrons, and electrons.

a neutral atom of manganese with a mass number of 55

25, 30, 25

argon-41

18, 23, 18

a potassium-39 cation with a +1 charge

19, 20, 18

A neutral atom of beryllium with a mass number of 9

4, 5, 4

hydrogen-3

1, 2, 1

a -3 anion of arsenic-75

33, 42, 36

88Sr2+

38

38, 50, 36

Which element is in group 6 of period 4?

•CHROMIUM

Which element has 4 valence electrons in the 2nd energy level?

•CARBON

Which alkali metal is located in period 4?

•POTASSIUM

Which of the following sets of elements are all in the same period on the periodic table?

A) manganese, calcium, argonB) zinc, copper, nitrogenC) sulfur, magnesium, silverD) rubidium, iodine, cadmium

•RB, I, CD

Which of the following elements experiences the most shielding?

aluminum mercury

arsenic rubidium•HG - 5 ENERGY LEVELS OF SHIELDING

Which of the following elements would have the smallest atomic radius?

As Ag Cr K•AS

Which of the following elements would have the lowest ionization energy?

Rb Sr Na Li

•RUBIDIUM

Which of the following elements would have the highest ionization energy?

K Ca As Kr•KRYPTON

Which of the following elements has the lowest electronegativity?

Si Sr Br O•STRONTIUM

What is the frequency of light with a wavelength of 560. nm?•5.36 E 14 HZ

Calculate the energy of a photon with a frequency of 7.35 E 8 Hz•4.87 E -25 J

Which of the following photons has the highest frequency?

=700 nm =3.5 E -7 nm=8.2 E 14 Hz•FREQUENCY AND WAVELENGTH ARE INVERSELY RELATED: HIGHEST FREQUENCY = SHORTEST WAVE

•=3.5 E -7 NM

Which of the following photons has the least energy?

=700 nm =3.5 E -7 nm

=8.2 E 14 Hz•ENERGY AND FREQUENCY ARE DIRECTLY RELATED: LOWEST ENERGY = LOWEST FREQUENCY = LONGEST WAVE

•=700 NM

Which of the following photons would be visible?

=275 nm =645 nm

=3.2 E -11 m

•=645 NM (BETWEEN 400 AND 750 NM)

Calculate the energy of a photon with a wavelength of 4.72 E -6 m•USE THE SPEED OF LIGHT EQUATION TO SOLVE FOR FREQUENCY

•FREQUENCY = 6.36 E 13 HZ

•USE THE FREQUENCY TO SOLVE FOR ENERGY

•4.21 E -20 J

__________ _________ is a measure of the energy it takes for an atom to lose 1 electron.•IONIZATION ENERGY